It’s the Genes After All!

Ötzi died 5,300 years ago. Today, he still has plenty to tell us as his remains provide startling insights for our modern life.

  • March 2017

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It’s the Genes After All!

Ötzi died 5,300 years ago. Today, he still has plenty to tell us as his remains provide startling insights for our modern life.

In 2007, Albert Zink began the strangest of relationships. Little did the anthropologist know at the time that Ötzi wasn’t the only mummified body he would research. Since that time, Zink has analysed specimens around the world as director of the EURAC research centre in Bolzano/Bozen. And yet it’s Ötzi, the world’s oldest iceman housed and displayed at the South Tyrol Museum of Archaeology, who still has so many secrets to tell. And Zink knows how to listen…

Scientists are often cool characters. So it was a bit of surprise to be welcomed so warmly by the good-humoured professor in his office. His message: Discoveries made possible by Ötzi’s remains defy established medical conventions.

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A Treasure Trove of Discovery from the Early Stone Age

Dr Zink, since his discovery Ötzi’s body has been intensely researched. What secrets do you yet hope to discover?
Albert Zink: Much of our research concerns questions about the development of illnesses over time, many of which still plague us today. In the past, we falsely concluded that heart or vascular diseases have only been a problem for the last century or so. Now, with the aid of computer tomography, we’ve discovered that Ötzi was affected by arteriosclerosis and was genetically disposed to many illnesses. Ötzi has also proven to be an important source of research for the development of diseases and changes over time.

What does that mean for us?
We had previously assumed that heart diseases were the result of an unhealthy diet, smoking, too little sport and obesity. Bear in mind, Ötzi was very slim, athletic, and moved about a lot. Nevertheless, Ötzi was genetically predisposed to certain conditions. In his old age, he would probably have suffered from serious heart problems or might have even had a heart attack. 

Ötzi's identity card

Eye colour

brown

Birthplace

Eisacktal

Age

46

Height

160 cm

Weight

50 kg

Year of birth

3,500 BC

Hair colour

brown

Interesting features

61 tattoos

Some Diseases are Like a Plague

Are there more “ancient” diseases or illnesses, which Ötzi may have suffered from?
Four years ago, we found Ötzi’s stomach. We were actually surprised that it was still intact. Because Ötzi was atop a rock in the glacier, his stomach had slipped below his rib cage. During our analysis, we found the bacterium Helicobacter pylori, which is present in nearly half of the world’s population. One in ten people develop gastritis from this bacterium or, in more rare cases, cancer. Whether Ötzi was troubled by any such symptoms is unknown.

But we do know what he ate before he died...
Yes, he consumed quite a bit of dried ibex meat and venison. Because Ötzi didn’t have any proper weapons to hunt with, he most likely ate the meat of dead animals that he found along the way. We also found grains. He must have had a type of bread or cereal porridge as a side dish of his final meal. In general, he had a very fatty diet from consuming meat, which we have research intensively because Ötzi was lactose intolerant.

How can you be sure he was lactose intolerant?
Ötzi’s lactose intolerance can be traced to a genetic mutation. In Ötzi’s day, people had just begun to use milk for adult nutrition, and not just for breast-feeding children. Nowadays, such intolerance is rare here in Europe where the use of milk has a long history. As an interesting contrast, many people are lactose intolerant in Africa, Asia and South America. 

A Giant Puzzle

Along with your team, you were able to decode Ötzi’s genome. How did you manage this?
This was made possible by the very latest technologies. We removed a very small piece of Ötzi’s pelvic bone, which was luckily still quite well preserved. This allowed us to extract his genome. These samples are then decoded with a DNA sequencing instrument, which allowed us discern the entire genetic sequence, which is comprised of millions of data sets. This in turn is fed into software for analysis, thereby allowing us to assemble the complete genome.

Like a puzzle...
Exactly. When everything was ‘put together,’ we were able to reconstruct 85% of Ötzi’s genome. This provided us with a wealth of information like hair colour and that Ötzi had brown eyes and not blue as previously assumed. 

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South Tyrol’s oldest resident

What did you learn from decoding Ötzi’s DNA?
We were able to compare Ötzi’s DNA with that of various different populations of people and found out that only very few people belong to this same group today. The majority live in what is now Sardinia. Nevertheless, Ötzi is not Sardinian. During the great migration, which took place 10,000 to 8,000 years ago, the entire European population immigrated to Europe from the Middle East. The DNA of Ötzi’s closest genetic relatives still remains relatively intact on the island.

Was Ötzi a South Tyrolean?
An analysis of Ötzi’s bones and teeth has led us to believe that Ötzi grew up in the Eisacktal valley and lived in the Vinschgau valley. At the Forensic Medicine Institute in Innsbruck, 4,000 samples from Tyroleans, other Austrians, and South Tyroleans were compared. Through this analysis, 19 people were identified as belonging to the same group as Ötzi. This shows that there are people here who are directly related to Ötzi, even if they are not ‘related.’ 

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The Iceman Box

Today, Ötzi “lives” in his own very special room at the South Tyrol Museum of Archaeology in Bolzano. Which conditions were necessary to ensure the perfect atmosphere for the famous iceman?   
Perfect? Perhaps not, but conditions here are similar to the environmental conditions where Ötzi’s remains were discovered. He was encased in ice and snow for so long that plenty of water (which we do our best to retain) was bound to his body. He is preserved at a temperature of -6 to -7°C with 98% humidity. In spite of these efforts, Ötzi loses approximately 1 to 2 grams of water per day, which simply evaporates. As a result, the iceman is sprayed with sterile water every two months.

At present, we are trying to develop an automatic system for this task. We are also concerned about a bacterium that grows on Ötzi and we are currently considering using nitrogen as with the other artefacts found. This would inhibit the oxidative processes, e.g. light reaction to oxygen, which can cause damage to the skin. From a technical perspective this is no problem, but we have to be careful considering that other types of bacteria could grow instead. The optimal way to preserve the body will continue to be an important topic.

Was Ötzi Fashionable?

Ötzi decorated his body with 61 tattoos. 60 of these tattoos are located along what we recognise today to be the main acupuncture lines. Now, Ötzi researcher Marco Samadelli in Bolzano has discovered an additional tattoo on the famous iceman directly on the rib cage on the right underside. It turns out that Ötzi wasn’t interested in fashion so much as reducing pain. Scientists now believe that the tattoos are really cuts for pain relief.

CSI Ötzi

The life of the oldest iceman in the world is as mysterious as his death. What is clear is that he was shot with an arrow from long distance. But were attempts made to hide his body?
We turned to the Criminal Investigation Department in Munich for answers in order to reconstruct what happened. After all, Ötzi was not robbed. His tools were found in the immediate area, including a copper arrowhead, which would have been valuable at the time. Of course, so many years later, a suspect would be hard to find. Nevertheless, a deep cut was discovered on his right hand, which was the result of close combat just a few days before his death. Was Ötzi involved in a conflict with his eventual murderer? And was Ötzi really as nice as he is always depicted, or was he perhaps a bad man himself?

Are there still things you definitely want to know about Ötzi?
What was his real name and what kind of a person was he. Was he courageous, shy or clever? I’d prefer to ask him myself. Actually, his brain is very well preserved. Perhaps we will someday develop a technique that will allow me to ask all of my many questions.

Interview: Dora Vannetiello, Stefanie Geier and Katja Schroffenegger
Transcreation: Covi, Wurzer & Partner - Die Sprachdienstleister
Photos: Alex Filz, Südtiroler Archäologiemuseum/foto-dpi.com and Augustin Ochsenreiter